# coding=utf-8
# Copyright 2023 The Intel Labs Team Authors, The Microsoft Research Team Authors and HuggingFace Inc. team. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
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"""PyTorch BridgeTower Model"""

from collections import OrderedDict
from dataclasses import dataclass
from typing import Callable, Optional, Union

import torch
from torch import nn
from torch.nn import CrossEntropyLoss

from ...activations import ACT2FN, QuickGELUActivation
from ...cache_utils import Cache, EncoderDecoderCache
from ...masking_utils import create_causal_mask
from ...modeling_attn_mask_utils import _prepare_4d_attention_mask, _prepare_4d_attention_mask_for_sdpa
from ...modeling_layers import GradientCheckpointingLayer
from ...modeling_outputs import (
    BaseModelOutputWithPastAndCrossAttentions,
    BaseModelOutputWithPoolingAndCrossAttentions,
    MaskedLMOutput,
    ModelOutput,
    SequenceClassifierOutput,
)
from ...modeling_utils import ALL_ATTENTION_FUNCTIONS, PreTrainedModel
from ...processing_utils import Unpack
from ...pytorch_utils import apply_chunking_to_forward, find_pruneable_heads_and_indices, prune_linear_layer
from ...utils import TransformersKwargs, auto_docstring, is_torch_flex_attn_available, logging, torch_int
from ...utils.generic import can_return_tuple
from .configuration_bridgetower import BridgeTowerConfig, BridgeTowerTextConfig, BridgeTowerVisionConfig


if is_torch_flex_attn_available():
    from ...integrations.flex_attention import make_flex_block_causal_mask


logger = logging.get_logger(__name__)

_TOKENIZER_FOR_DOC = "RobertaTokenizer"


@dataclass
@auto_docstring(
    custom_intro="""
    Output type of [`BridgeTowerModel`].
    """
)
class BridgeTowerModelOutput(ModelOutput):
    r"""
    text_features (`torch.FloatTensor` of shape `(batch_size, text_sequence_length, hidden_size)`):
        Sequence of hidden-states at the text output of the last layer of the model.
    image_features (`torch.FloatTensor` of shape `(batch_size, image_sequence_length, hidden_size)`):
        Sequence of hidden-states at the image output of the last layer of the model.
    pooler_output (`torch.FloatTensor` of shape `(batch_size, hidden_size x 2)`):
        Concatenation of last layer hidden-state of the first token of the text and image sequence (classification
        token), respectively, after further processing through layers used for auxiliary pretraining tasks.
    """

    text_features: Optional[torch.FloatTensor] = None
    image_features: Optional[torch.FloatTensor] = None
    pooler_output: Optional[torch.FloatTensor] = None
    hidden_states: Optional[tuple[torch.FloatTensor]] = None
    attentions: Optional[tuple[torch.FloatTensor]] = None


@dataclass
@auto_docstring(
    custom_intro="""
    Output type of ['BridgeTowerForContrastiveLearning']
    """
)
class BridgeTowerContrastiveOutput(ModelOutput):
    r"""
    loss (`torch.FloatTensor` of shape `(1,)`, *optional*, returned when `return_loss` is `True`):
        Image-text contrastive loss.
    logits (`torch.FloatTensor` of shape `(batch_size, sequence_length, config.vocab_size)`):
        Prediction scores of the language modeling head (scores for each vocabulary token before SoftMax).
    text_embeds (`torch.FloatTensor)`, *optional*, returned when model is initialized with `with_projection=True`):
        The text embeddings obtained by applying the projection layer to the pooler_output.
    image_embeds (`torch.FloatTensor)`, *optional*, returned when model is initialized with `with_projection=True`):
        The image embeddings obtained by applying the projection layer to the pooler_output.
    cross_embeds (`torch.FloatTensor)`, *optional*, returned when model is initialized with `with_projection=True`):
        The text-image cross-modal embeddings obtained by applying the projection layer to the pooler_output.
    attentions (`tuple(torch.FloatTensor)`, *optional*, returned when `output_attentions=True` is passed or when `config.output_attentions=True`):
        Tuple of `torch.FloatTensor` (one for each layer) of shape `(batch_size, num_heads, sequence_length,
        sequence_length)`.
    """

    loss: Optional[torch.FloatTensor] = None
    logits: Optional[torch.FloatTensor] = None
    text_embeds: Optional[tuple[torch.FloatTensor]] = None
    image_embeds: Optional[tuple[torch.FloatTensor]] = None
    cross_embeds: Optional[tuple[torch.FloatTensor]] = None
    hidden_states: Optional[tuple[torch.FloatTensor]] = None
    attentions: Optional[tuple[torch.FloatTensor]] = None


class BridgeTowerResidualAttention(nn.Module):
    def __init__(self, config):
        super().__init__()

        self.attn = nn.MultiheadAttention(config.hidden_size, config.hidden_size // 64)
        self.ln_1 = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps)
        self.mlp = nn.ModuleDict(
            OrderedDict(
                [
                    ("c_fc", nn.Linear(config.hidden_size, config.hidden_size * 4)),
                    ("gelu", QuickGELUActivation()),
                    ("c_proj", nn.Linear(config.hidden_size * 4, config.hidden_size)),
                ]
            )
        )
        self.ln_2 = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps)
        self.attn_mask = None

    def attention(self, hidden_state: torch.Tensor, attention_mask: torch.Tensor):
        if attention_mask is not None:
            attention_mask = attention_mask.to(dtype=torch.bool, device=hidden_state.device)
        self.attn_mask = (
            self.attn_mask.to(dtype=hidden_state.dtype, device=hidden_state.device)
            if self.attn_mask is not None
            else None
        )
        return self.attn(
            hidden_state,
            hidden_state,
            hidden_state,
            need_weights=False,
            attn_mask=self.attn_mask,
            key_padding_mask=attention_mask,
        )[0]

    def forward(self, hidden_state: torch.Tensor, attention_mask: Optional[torch.Tensor] = None):
        residual_state = hidden_state + self.attention(self.ln_1(hidden_state), attention_mask)
        hidden_state = self.ln_2(residual_state)
        for layer in self.mlp.values():
            hidden_state = layer(hidden_state)
        hidden_state = residual_state + hidden_state
        return hidden_state


class BridgeTowerTransformer(nn.Module):
    def __init__(self, config):
        super().__init__()
        self.hidden_size = config.hidden_size
        self.num_hidden_layers = config.num_hidden_layers
        if config.remove_last_layer:
            self.resblocks = nn.ModuleList(
                [BridgeTowerResidualAttention(config) for _ in range(self.num_hidden_layers - 1)]
            )
        else:
            self.resblocks = nn.ModuleList(
                [BridgeTowerResidualAttention(config) for _ in range(self.num_hidden_layers)]
            )
        self.stop_gradient = config.stop_gradient

    def forward(self, hidden_state: torch.Tensor, attention_mask: Optional[torch.Tensor] = None):
        hidden_states = []
        for block in self.resblocks:
            hidden_state = block(hidden_state, attention_mask)
            if self.stop_gradient:
                hidden_states.append(hidden_state.detach())
            else:
                hidden_states.append(hidden_state)
        return hidden_states


# Copied from transformers.models.clip.modeling_clip.CLIPVisionEmbeddings with CLIP->BridgeTower
class BridgeTowerVisionEmbeddings(nn.Module):
    def __init__(self, config: BridgeTowerVisionConfig):
        super().__init__()
        self.config = config
        self.embed_dim = config.hidden_size
        self.image_size = config.image_size
        self.patch_size = config.patch_size

        self.class_embedding = nn.Parameter(torch.randn(self.embed_dim))

        self.patch_embedding = nn.Conv2d(
            in_channels=config.num_channels,
            out_channels=self.embed_dim,
            kernel_size=self.patch_size,
            stride=self.patch_size,
            bias=False,
        )

        self.num_patches = (self.image_size // self.patch_size) ** 2
        self.num_positions = self.num_patches + 1
        self.position_embedding = nn.Embedding(self.num_positions, self.embed_dim)
        self.register_buffer("position_ids", torch.arange(self.num_positions).expand((1, -1)), persistent=False)

    def interpolate_pos_encoding(self, embeddings: torch.Tensor, height: int, width: int) -> torch.Tensor:
        """
        This method allows to interpolate the pre-trained position encodings, to be able to use the model on higher resolution
        images. This method is also adapted to support torch.jit tracing.

        Adapted from:
        - https://github.com/facebookresearch/dino/blob/de9ee3df6cf39fac952ab558447af1fa1365362a/vision_transformer.py#L174-L194, and
        - https://github.com/facebookresearch/dinov2/blob/e1277af2ba9496fbadf7aec6eba56e8d882d1e35/dinov2/models/vision_transformer.py#L179-L211
        """

        num_patches = embeddings.shape[1] - 1
        position_embedding = self.position_embedding.weight.unsqueeze(0)
        num_positions = position_embedding.shape[1] - 1

        # always interpolate when tracing to ensure the exported model works for dynamic input shapes
        if not torch.jit.is_tracing() and num_patches == num_positions and height == width:
            return self.position_embedding(self.position_ids)

        class_pos_embed = position_embedding[:, :1]
        patch_pos_embed = position_embedding[:, 1:]

        dim = embeddings.shape[-1]

        new_height = height // self.patch_size
        new_width = width // self.patch_size

        sqrt_num_positions = torch_int(num_positions**0.5)
        patch_pos_embed = patch_pos_embed.reshape(1, sqrt_num_positions, sqrt_num_positions, dim)
        patch_pos_embed = patch_pos_embed.permute(0, 3, 1, 2)

        patch_pos_embed = nn.functional.interpolate(
            patch_pos_embed,
            size=(new_height, new_width),
            mode="bicubic",
            align_corners=False,
        )

        patch_pos_embed = patch_pos_embed.permute(0, 2, 3, 1).view(1, -1, dim)

        return torch.cat((class_pos_embed, patch_pos_embed), dim=1)

    def forward(self, pixel_values: torch.FloatTensor, interpolate_pos_encoding=False) -> torch.Tensor:
        batch_size, _, height, width = pixel_values.shape
        if not interpolate_pos_encoding and (height != self.image_size or width != self.image_size):
            raise ValueError(
                f"Input image size ({height}*{width}) doesn't match model ({self.image_size}*{self.image_size})."
            )
        target_dtype = self.patch_embedding.weight.dtype
        patch_embeds = self.patch_embedding(pixel_values.to(dtype=target_dtype))  # shape = [*, width, grid, grid]
        patch_embeds = patch_embeds.flatten(2).transpose(1, 2)

        class_embeds = self.class_embedding.expand(batch_size, 1, -1)
        embeddings = torch.cat([class_embeds, patch_embeds], dim=1)
        if interpolate_pos_encoding:
            embeddings = embeddings + self.interpolate_pos_encoding(embeddings, height, width)
        else:
            embeddings = embeddings + self.position_embedding(self.position_ids)
        return embeddings


class BridgeTowerVisionTransformer(nn.Module):
    def __init__(self, config):
        super().__init__()

        self.embeddings = BridgeTowerVisionEmbeddings(config)
        self.ln_pre = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps)
        self.transformer = BridgeTowerTransformer(config)
        self.ln_post = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps)
        self.share_layernorm = config.share_layernorm
        if not config.share_layernorm:
            self.ln_separate = nn.ModuleList(
                [nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps) for _ in range(config.num_hidden_layers)]
            )

    def forward(
        self,
        pixel_values: torch.Tensor,
        attention_mask,
        interpolate_pos_encoding: bool = False,
    ):
        hidden_states = self.embeddings(pixel_values, interpolate_pos_encoding)
        hidden_states = self.ln_pre(hidden_states)
        # NLD -> LND
        hidden_states = hidden_states.permute(1, 0, 2)

        hidden_states = self.transformer(hidden_states, attention_mask)
        # shape = [num_hidden_layers, hidden_size, *, grid ** 2]
        hidden_states = torch.stack(hidden_states, dim=0)
        # shape = [num_hidden_layers, *, hidden_size, grid ** 2]
        hidden_states = hidden_states.permute(0, 2, 1, 3)
        if self.share_layernorm:
            hidden_states = self.ln_post(hidden_states)
        else:
            hidden_states_stack = []
            for hidden_states, ln in zip(hidden_states, self.ln_separate):
                hidden_states = ln(hidden_states)
                hidden_states_stack.append(hidden_states)
            # shape = [num_hidden_layers, *, hidden_size, grid ** 2]
            hidden_states = torch.stack(hidden_states_stack, dim=0)
        return hidden_states

    def forward_pre(
        self,
        pixel_values: torch.Tensor,
        interpolate_pos_encoding: bool = False,
    ):
        hidden_states = self.embeddings(pixel_values, interpolate_pos_encoding=interpolate_pos_encoding)
        hidden_states = self.ln_pre(hidden_states)
        # NLD -> LND
        hidden_states = hidden_states.permute(1, 0, 2)
        return hidden_states

    def forward_post(self, hidden_state: torch.Tensor):
        visual_output_post = hidden_state.permute(1, 0, 2)
        visual_output_post = self.ln_post(visual_output_post)
        return visual_output_post


class BridgeTowerLinkTower(nn.Module):
    def __init__(self, config):
        super().__init__()
        self.link_tower_type = config.link_tower_type
        self.hidden_size = config.hidden_size
        if config.link_tower_type in ["add", "scaled_add", "interpolate"]:
            if config.link_tower_type == "scaled_add":
                self.scaled_factor = nn.Parameter(torch.tensor(1.0))
            elif config.link_tower_type == "interpolate":
                self.beta = nn.Parameter(torch.tensor(0.5))
            self.LayerNorm = nn.LayerNorm(self.hidden_size, eps=config.layer_norm_eps)
        else:
            raise NotImplementedError(f"link_tower_type {config.link_tower_type} is not implemented")

    def forward(self, hidden_states, cross_modal_hidden_states, attention_mask):
        if self.link_tower_type == "add":
            return self.LayerNorm(hidden_states + cross_modal_hidden_states)
        elif self.link_tower_type == "scaled_add":
            return self.LayerNorm(hidden_states * self.scaled_factor + cross_modal_hidden_states)
        elif self.link_tower_type == "interpolate":
            return self.LayerNorm(hidden_states * (1 - self.beta) + cross_modal_hidden_states * self.beta)
        else:
            raise NotImplementedError(f"link_tower_type {self.link_tower_type} is not implemented")


# Copied from transformers.models.bert.modeling_bert.BertSelfOutput with Bert->BridgeTower
class BridgeTowerSelfOutput(nn.Module):
    def __init__(self, config):
        super().__init__()
        self.dense = nn.Linear(config.hidden_size, config.hidden_size)
        self.LayerNorm = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps)
        self.dropout = nn.Dropout(config.hidden_dropout_prob)

    def forward(self, hidden_states: torch.Tensor, input_tensor: torch.Tensor) -> torch.Tensor:
        hidden_states = self.dense(hidden_states)
        hidden_states = self.dropout(hidden_states)
        hidden_states = self.LayerNorm(hidden_states + input_tensor)
        return hidden_states


# Copied from transformers.models.bert.modeling_bert.BertIntermediate with Bert->BridgeTower
class BridgeTowerIntermediate(nn.Module):
    def __init__(self, config):
        super().__init__()
        self.dense = nn.Linear(config.hidden_size, config.intermediate_size)
        if isinstance(config.hidden_act, str):
            self.intermediate_act_fn = ACT2FN[config.hidden_act]
        else:
            self.intermediate_act_fn = config.hidden_act

    def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
        hidden_states = self.dense(hidden_states)
        hidden_states = self.intermediate_act_fn(hidden_states)
        return hidden_states


# Copied from transformers.models.bert.modeling_bert.BertOutput with Bert->BridgeTower
class BridgeTowerOutput(nn.Module):
    def __init__(self, config):
        super().__init__()
        self.dense = nn.Linear(config.intermediate_size, config.hidden_size)
        self.LayerNorm = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps)
        self.dropout = nn.Dropout(config.hidden_dropout_prob)

    def forward(self, hidden_states: torch.Tensor, input_tensor: torch.Tensor) -> torch.Tensor:
        hidden_states = self.dense(hidden_states)
        hidden_states = self.dropout(hidden_states)
        hidden_states = self.LayerNorm(hidden_states + input_tensor)
        return hidden_states


# Copied from transformers.models.bert.modeling_bert.BertPooler with Bert->BridgeTower
class BridgeTowerPooler(nn.Module):
    def __init__(self, config):
        super().__init__()
        self.dense = nn.Linear(config.hidden_size, config.hidden_size)
        self.activation = nn.Tanh()

    def forward(self, hidden_states: torch.Tensor) -> torch.Tensor:
        # We "pool" the model by simply taking the hidden state corresponding
        # to the first token.
        first_token_tensor = hidden_states[:, 0]
        pooled_output = self.dense(first_token_tensor)
        pooled_output = self.activation(pooled_output)
        return pooled_output


# Copied from transformers.models.bert.modeling_bert.eager_attention_forward
def eager_attention_forward(
    module: nn.Module,
    query: torch.Tensor,
    key: torch.Tensor,
    value: torch.Tensor,
    attention_mask: Optional[torch.Tensor],
    scaling: Optional[float] = None,
    dropout: float = 0.0,
    head_mask: Optional[torch.Tensor] = None,
    use_cache: Optional[bool] = None,
    **kwargs: Unpack[TransformersKwargs],
):
    if scaling is None:
        scaling = query.size(-1) ** -0.5

    # Take the dot product between "query" and "key" to get the raw attention scores.
    attn_weights = torch.matmul(query, key.transpose(2, 3))

    # Relative positional embeddings
    if module.position_embedding_type == "relative_key" or module.position_embedding_type == "relative_key_query":
        query_length, key_length = query.shape[2], key.shape[2]
        if use_cache:
            position_ids_l = torch.tensor(key_length - 1, dtype=torch.long, device=query.device).view(-1, 1)
        else:
            position_ids_l = torch.arange(query_length, dtype=torch.long, device=query.device).view(-1, 1)
        position_ids_r = torch.arange(key_length, dtype=torch.long, device=query.device).view(1, -1)
        distance = position_ids_l - position_ids_r

        positional_embedding = module.distance_embedding(distance + module.max_position_embeddings - 1)
        positional_embedding = positional_embedding.to(dtype=query.dtype)  # fp16 compatibility

        if module.position_embedding_type == "relative_key":
            relative_position_scores = torch.einsum("bhld,lrd->bhlr", query, positional_embedding)
            attn_weights = attn_weights + relative_position_scores
        elif module.position_embedding_type == "relative_key_query":
            relative_position_scores_query = torch.einsum("bhld,lrd->bhlr", query, positional_embedding)
            relative_position_scores_key = torch.einsum("bhrd,lrd->bhlr", key, positional_embedding)
            attn_weights = attn_weights + relative_position_scores_query + relative_position_scores_key

    # Scaling is shifted in case of embeddings being relative
    attn_weights = attn_weights * scaling

    if attention_mask is not None and attention_mask.ndim == 4:
        attention_mask = attention_mask[:, :, :, : key.shape[-2]]
        attn_weights = attn_weights + attention_mask

    attn_weights = nn.functional.softmax(attn_weights, dim=-1)
    attn_weights = nn.functional.dropout(attn_weights, p=dropout, training=module.training)

    if head_mask is not None:
        attn_weights = attn_weights * head_mask

    attn_output = torch.matmul(attn_weights, value)
    attn_output = attn_output.transpose(1, 2).contiguous()

    return attn_output, attn_weights


# Copied from transformers.models.roberta.modeling_roberta.RobertaSelfAttention with Roberta->BridgeTower
class BridgeTowerSelfAttention(nn.Module):
    def __init__(self, config, position_embedding_type=None, is_causal=False, layer_idx=None):
        super().__init__()
        if config.hidden_size % config.num_attention_heads != 0 and not hasattr(config, "embedding_size"):
            raise ValueError(
                f"The hidden size ({config.hidden_size}) is not a multiple of the number of attention "
                f"heads ({config.num_attention_heads})"
            )
        self.config = config

        self.num_attention_heads = config.num_attention_heads
        self.attention_head_size = int(config.hidden_size / config.num_attention_heads)
        self.all_head_size = self.num_attention_heads * self.attention_head_size
        self.scaling = self.attention_head_size**-0.5

        self.query = nn.Linear(config.hidden_size, self.all_head_size)
        self.key = nn.Linear(config.hidden_size, self.all_head_size)
        self.value = nn.Linear(config.hidden_size, self.all_head_size)

        self.dropout = nn.Dropout(config.attention_probs_dropout_prob)
        self.position_embedding_type = position_embedding_type or getattr(
            config, "position_embedding_type", "absolute"
        )
        if self.position_embedding_type == "relative_key" or self.position_embedding_type == "relative_key_query":
            self.max_position_embeddings = config.max_position_embeddings
            self.distance_embedding = nn.Embedding(2 * config.max_position_embeddings - 1, self.attention_head_size)

        self.is_decoder = config.is_decoder
        self.is_causal = is_causal
        self.layer_idx = layer_idx

    def forward(
        self,
        hidden_states: torch.Tensor,
        attention_mask: Optional[torch.FloatTensor] = None,
        head_mask: Optional[torch.FloatTensor] = None,
        past_key_value: Optional[Cache] = None,
        cache_position: Optional[torch.Tensor] = None,
        **kwargs: Unpack[TransformersKwargs],
    ) -> tuple[torch.Tensor]:
        input_shape = hidden_states.shape[:-1]
        hidden_shape = (*input_shape, -1, self.attention_head_size)

        # get all proj
        query_layer = self.query(hidden_states).view(*hidden_shape).transpose(1, 2)
        key_layer = self.key(hidden_states).view(*hidden_shape).transpose(1, 2)
        value_layer = self.value(hidden_states).view(*hidden_shape).transpose(1, 2)

        if past_key_value is not None:
            # decoder-only roberta can have a simple dynamic cache for example
            current_past_key_value = past_key_value
            if isinstance(past_key_value, EncoderDecoderCache):
                current_past_key_value = past_key_value.self_attention_cache

            # save all key/value_layer to cache to be re-used for fast auto-regressive generation
            key_layer, value_layer = current_past_key_value.update(
                key_layer,
                value_layer,
                self.layer_idx,
                {"cache_position": cache_position},
            )

        attention_interface: Callable = eager_attention_forward
        if self.config._attn_implementation != "eager":
            if self.position_embedding_type != "absolute":
                raise ValueError(
                    f"You are using {self.config._attn_implementation} as attention type. However, non-absolute "
                    'positional embeddings can not work with them. Please load the model with `attn_implementation="eager"`.'
                )
            attention_interface = ALL_ATTENTION_FUNCTIONS[self.config._attn_implementation]

        attn_output, attn_weights = attention_interface(
            self,
            query_layer,
            key_layer,
            value_layer,
            attention_mask,
            dropout=0.0 if not self.training else self.dropout.p,
            scaling=self.scaling,
            head_mask=head_mask,
            # only for relevant for non-absolute positional embeddings
            use_cache=past_key_value is not None,
            **kwargs,
        )
        attn_output = attn_output.reshape(*input_shape, -1).contiguous()
        return attn_output, attn_weights


# Copied from transformers.models.roberta.modeling_roberta.RobertaCrossAttention with Roberta->BridgeTower
class BridgeTowerCrossAttention(nn.Module):
    def __init__(self, config, position_embedding_type=None, is_causal=False, layer_idx=None):
        super().__init__()
        if config.hidden_size % config.num_attention_heads != 0 and not hasattr(config, "embedding_size"):
            raise ValueError(
                f"The hidden size ({config.hidden_size}) is not a multiple of the number of attention "
                f"heads ({config.num_attention_heads})"
            )
        self.config = config

        self.num_attention_heads = config.num_attention_heads
        self.attention_head_size = int(config.hidden_size / config.num_attention_heads)
        self.all_head_size = self.num_attention_heads * self.attention_head_size
        self.scaling = self.attention_head_size**-0.5

        self.query = nn.Linear(config.hidden_size, self.all_head_size)
        self.key = nn.Linear(config.hidden_size, self.all_head_size)
        self.value = nn.Linear(config.hidden_size, self.all_head_size)

        self.dropout = nn.Dropout(config.attention_probs_dropout_prob)
        self.position_embedding_type = position_embedding_type or getattr(
            config, "position_embedding_type", "absolute"
        )
        if self.position_embedding_type == "relative_key" or self.position_embedding_type == "relative_key_query":
            self.max_position_embeddings = config.max_position_embeddings
            self.distance_embedding = nn.Embedding(2 * config.max_position_embeddings - 1, self.attention_head_size)

        self.is_causal = is_causal
        self.layer_idx = layer_idx

    def forward(
        self,
        hidden_states: torch.Tensor,
        encoder_hidden_states: Optional[torch.FloatTensor] = None,
        attention_mask: Optional[torch.FloatTensor] = None,
        head_mask: Optional[torch.FloatTensor] = None,
        past_key_value: Optional[EncoderDecoderCache] = None,
        **kwargs: Unpack[TransformersKwargs],
    ) -> tuple[torch.Tensor]:
        # determine input shapes
        bsz, tgt_len = hidden_states.shape[:-1]
        src_len = encoder_hidden_states.shape[1]

        q_input_shape = (bsz, tgt_len, -1, self.attention_head_size)
        kv_input_shape = (bsz, src_len, -1, self.attention_head_size)

        # get query proj
        query_layer = self.query(hidden_states).view(*q_input_shape).transpose(1, 2)

        is_updated = past_key_value.is_updated.get(self.layer_idx) if past_key_value is not None else False
        if past_key_value is not None and is_updated:
            # reuse k,v, cross_attentions
            key_layer = past_key_value.cross_attention_cache.layers[self.layer_idx].keys
            value_layer = past_key_value.cross_attention_cache.layers[self.layer_idx].values
        else:
            key_layer = self.key(encoder_hidden_states).view(*kv_input_shape).transpose(1, 2)
            value_layer = self.value(encoder_hidden_states).view(*kv_input_shape).transpose(1, 2)

            if past_key_value is not None:
                # save all states to the cache
                key_layer, value_layer = past_key_value.cross_attention_cache.update(
                    key_layer, value_layer, self.layer_idx
                )
                # set flag that curr layer for cross-attn is already updated so we can re-use in subsequent calls
                past_key_value.is_updated[self.layer_idx] = True

        attention_interface: Callable = eager_attention_forward
        if self.config._attn_implementation != "eager":
            if self.position_embedding_type != "absolute":
                raise ValueError(
                    f"You are using {self.config._attn_implementation} as attention type. However, non-absolute "
                    'positional embeddings can not work with them. Please load the model with `attn_implementation="eager"`.'
                )
            attention_interface = ALL_ATTENTION_FUNCTIONS[self.config._attn_implementation]

        attn_output, attn_weights = attention_interface(
            self,
            query_layer,
            key_layer,
            value_layer,
            attention_mask,
            dropout=0.0 if not self.training else self.dropout.p,
            scaling=self.scaling,
            head_mask=head_mask,
            # only for relevant for non-absolute positional embeddings
            use_cache=past_key_value is not None,
            **kwargs,
        )
        attn_output = attn_output.reshape(bsz, tgt_len, -1).contiguous()
        return attn_output, attn_weights


# Copied from transformers.models.bert.modeling_bert.BertAttention with Bert->BridgeTower,BERT->BRIDGE_TOWER
class BridgeTowerAttention(nn.Module):
    def __init__(
        self, config, position_embedding_type=None, is_causal=False, layer_idx=None, is_cross_attention=False
    ):
        super().__init__()
        self.is_cross_attention = is_cross_attention
        attention_class = BridgeTowerCrossAttention if is_cross_attention else BridgeTowerSelfAttention
        self.self = attention_class(
            config, position_embedding_type=position_embedding_type, is_causal=is_causal, layer_idx=layer_idx
        )
        self.output = BridgeTowerSelfOutput(config)
        self.pruned_heads = set()

    def prune_heads(self, heads):
        if len(heads) == 0:
            return
        heads, index = find_pruneable_heads_and_indices(
            heads, self.self.num_attention_heads, self.self.attention_head_size, self.pruned_heads
        )

        # Prune linear layers
        self.self.query = prune_linear_layer(self.self.query, index)
        self.self.key = prune_linear_layer(self.self.key, index)
        self.self.value = prune_linear_layer(self.self.value, index)
        self.output.dense = prune_linear_layer(self.output.dense, index, dim=1)

        # Update hyper params and store pruned heads
        self.self.num_attention_heads = self.self.num_attention_heads - len(heads)
        self.self.all_head_size = self.self.attention_head_size * self.self.num_attention_heads
        self.pruned_heads = self.pruned_heads.union(heads)

    def forward(
        self,
        hidden_states: torch.Tensor,
        attention_mask: Optional[torch.FloatTensor] = None,
        head_mask: Optional[torch.FloatTensor] = None,
        encoder_hidden_states: Optional[torch.FloatTensor] = None,
        encoder_attention_mask: Optional[torch.FloatTensor] = None,
        past_key_value: Optional[Cache] = None,
        cache_position: Optional[torch.Tensor] = None,
        **kwargs: Unpack[TransformersKwargs],
    ) -> tuple[torch.Tensor]:
        attention_mask = attention_mask if not self.is_cross_attention else encoder_attention_mask
        attention_output, attn_weights = self.self(
            hidden_states,
            encoder_hidden_states=encoder_hidden_states,
            attention_mask=attention_mask,
            head_mask=head_mask,
            past_key_value=past_key_value,
            cache_position=cache_position,
            **kwargs,
        )
        attention_output = self.output(attention_output, hidden_states)
        return attention_output, attn_weights


class BridgeTowerBertCrossLayer(nn.Module):
    def __init__(self, config, layer_idx=None):
        super().__init__()
        self.chunk_size_feed_forward = config.chunk_size_feed_forward
        self.seq_len_dim = 1
        self.attention = BridgeTowerAttention(config, is_causal=True, layer_idx=layer_idx)
        self.is_decoder = config.is_decoder
        self.add_cross_attention = config.add_cross_attention
        self.crossattention = BridgeTowerAttention(
            config,
            position_embedding_type="absolute",
            is_causal=False,
            layer_idx=layer_idx,
            is_cross_attention=True,
        )
        self.intermediate = BridgeTowerIntermediate(config)
        self.output = BridgeTowerOutput(config)

    def forward(
        self,
        hidden_states,
        encoder_hidden_states,
        attention_mask=None,
        head_mask=None,
        encoder_attention_mask=None,
        past_key_value=None,
        **kwargs: Unpack[TransformersKwargs],
    ):
        self_attention_output, self_attn_weights = self.attention(
            hidden_states,
            attention_mask=attention_mask,
            head_mask=None,
            past_key_value=None,
            **kwargs,
        )
        attention_output = self_attention_output

        cross_attention_output, cross_attn_weights = self.crossattention(
            attention_output,
            attention_mask=attention_mask,
            head_mask=head_mask,
            encoder_hidden_states=encoder_hidden_states,
            encoder_attention_mask=encoder_attention_mask,
            past_key_value=past_key_value,
            **kwargs,
        )
        attention_output = cross_attention_output

        layer_output = apply_chunking_to_forward(
            self.feed_forward_chunk, self.chunk_size_feed_forward, self.seq_len_dim, attention_output
        )
        return (
            layer_output,
            self_attn_weights,
            cross_attn_weights,
        )

    def feed_forward_chunk(self, attention_output):
        intermediate_output = self.intermediate(attention_output)
        layer_output = self.output(intermediate_output, attention_output)
        return layer_output


class BridgeTowerTextLayer(GradientCheckpointingLayer):
    def __init__(self, config, layer_idx=None):
        super().__init__()
        self.chunk_size_feed_forward = config.chunk_size_feed_forward
        self.seq_len_dim = 1
        self.attention = BridgeTowerAttention(config, is_causal=config.is_decoder, layer_idx=layer_idx)
        self.is_decoder = config.is_decoder
        self.add_cross_attention = config.add_cross_attention
        if self.add_cross_attention:
            if not self.is_decoder:
                raise ValueError(f"{self} should be used as a decoder model if cross attention is added")
            self.crossattention = BridgeTowerAttention(
                config,
                position_embedding_type="absolute",
                is_causal=False,
                layer_idx=layer_idx,
                is_cross_attention=True,
            )
        self.intermediate = BridgeTowerIntermediate(config)
        self.output = BridgeTowerOutput(config)

    # copied from transformers.models.bert.modeling_bert.BertLayer.forward
    def forward(
        self,
        hidden_states: torch.Tensor,
        attention_mask: Optional[torch.FloatTensor] = None,
        head_mask: Optional[torch.FloatTensor] = None,
        encoder_hidden_states: Optional[torch.FloatTensor] = None,
        encoder_attention_mask: Optional[torch.FloatTensor] = None,
        past_key_value: Optional[Cache] = None,
        cache_position: Optional[torch.Tensor] = None,
        **kwargs: Unpack[TransformersKwargs],
    ) -> tuple[torch.Tensor]:
        outputs = ()
        self_attention_output, self_attn_weights = self.attention(
            hidden_states,
            attention_mask,
            head_mask,
            past_key_value=past_key_value,
            cache_position=cache_position,
            **kwargs,
        )
        attention_output = self_attention_output

        if self.is_decoder and encoder_hidden_states is not None:
            if not hasattr(self, "crossattention"):
                raise ValueError(
                    f"If `encoder_hidden_states` are passed, {self} has to be instantiated with cross-attention layers"
                    " by setting `config.add_cross_attention=True`"
                )

            cross_attention_output, cross_attn_weights = self.crossattention(
                self_attention_output,
                None,  # attention_mask
                head_mask,
                encoder_hidden_states,
                encoder_attention_mask,
                past_key_value=past_key_value,
                **kwargs,
            )
            attention_output = cross_attention_output
            outputs = (cross_attn_weights,)

        layer_output = apply_chunking_to_forward(
            self.feed_forward_chunk, self.chunk_size_feed_forward, self.seq_len_dim, attention_output
        )
        return outputs + (
            layer_output,
            self_attn_weights,
        )

    def feed_forward_chunk(self, attention_output):
        intermediate_output = self.intermediate(attention_output)
        layer_output = self.output(intermediate_output, attention_output)
        return layer_output


# copied from transformers.models.roberta.modeling_roberta.RobertaEncoder with Roberta->BridgeTowerText
class BridgeTowerTextEncoder(nn.Module):
    def __init__(self, config):
        super().__init__()
        self.config = config
        self.layer = nn.ModuleList(
            [BridgeTowerTextLayer(config, layer_idx=i) for i in range(config.num_hidden_layers)]
        )

    def forward(
        self,
        hidden_states: torch.Tensor,
        attention_mask: Optional[torch.FloatTensor] = None,
        head_mask: Optional[torch.FloatTensor] = None,
        encoder_hidden_states: Optional[torch.FloatTensor] = None,
        encoder_attention_mask: Optional[torch.FloatTensor] = None,
        past_key_values: Optional[Cache] = None,
        use_cache: Optional[bool] = None,
        output_attentions: Optional[bool] = False,
        output_hidden_states: Optional[bool] = False,
        cache_position: Optional[torch.Tensor] = None,
        **kwargs: Unpack[TransformersKwargs],
    ) -> Union[tuple[torch.Tensor], BaseModelOutputWithPastAndCrossAttentions]:
        all_hidden_states = () if output_hidden_states else None
        all_self_attentions = () if output_attentions else None
        all_cross_attentions = () if output_attentions and self.config.add_cross_attention else None

        for i, layer_module in enumerate(self.layer):
            layer_head_mask = head_mask[i] if head_mask is not None else None

            layer_outputs = layer_module(
                hidden_states,
                attention_mask,
                layer_head_mask,
                encoder_hidden_states,  # as a positional argument for gradient checkpointing
                encoder_attention_mask=encoder_attention_mask,
                past_key_value=past_key_values,
                cache_position=cache_position,
                **kwargs,
            )

            hidden_states = layer_outputs[0]
            if output_attentions:
                all_self_attentions = all_self_attentions + (layer_outputs[1],)
                if self.config.add_cross_attention:
                    all_cross_attentions = all_cross_attentions + (layer_outputs[2],)

        if output_hidden_states:
            all_hidden_states = all_hidden_states + (hidden_states,)

        return BaseModelOutputWithPastAndCrossAttentions(
            last_hidden_state=hidden_states,
            past_key_values=past_key_values if use_cache else None,
            hidden_states=all_hidden_states,
            attentions=all_self_attentions,
            cross_attentions=all_cross_attentions,
        )


# Copied from transformers.models.roberta.modeling_roberta.RobertaEmbeddings with Roberta->BridgeTowerText
class BridgeTowerTextEmbeddings(nn.Module):
    """Construct the embeddings from word, position and token_type embeddings."""

    def __init__(self, config):
        super().__init__()
        self.word_embeddings = nn.Embedding(config.vocab_size, config.hidden_size, padding_idx=config.pad_token_id)
        self.token_type_embeddings = nn.Embedding(config.type_vocab_size, config.hidden_size)

        self.LayerNorm = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps)
        self.dropout = nn.Dropout(config.hidden_dropout_prob)
        # position_ids (1, len position emb) is contiguous in memory and exported when serialized
        self.position_embedding_type = getattr(config, "position_embedding_type", "absolute")
        self.register_buffer(
            "position_ids", torch.arange(config.max_position_embeddings).expand((1, -1)), persistent=False
        )
        self.register_buffer(
            "token_type_ids", torch.zeros(self.position_ids.size(), dtype=torch.long), persistent=False
        )

        self.padding_idx = config.pad_token_id
        self.position_embeddings = nn.Embedding(
            config.max_position_embeddings, config.hidden_size, padding_idx=self.padding_idx
        )

    def forward(
        self,
        input_ids: Optional[torch.LongTensor] = None,
        token_type_ids: Optional[torch.LongTensor] = None,
        position_ids: Optional[torch.LongTensor] = None,
        inputs_embeds: Optional[torch.FloatTensor] = None,
        past_key_values_length: int = 0,
    ) -> torch.Tensor:
        if position_ids is None:
            if input_ids is not None:
                # Create the position ids from the input token ids. Any padded tokens remain padded.
                position_ids = self.create_position_ids_from_input_ids(
                    input_ids, self.padding_idx, past_key_values_length
                )
            else:
                position_ids = self.create_position_ids_from_inputs_embeds(inputs_embeds, self.padding_idx)

        if input_ids is not None:
            input_shape = input_ids.size()
        else:
            input_shape = inputs_embeds.size()[:-1]

        batch_size, seq_length = input_shape

        # Setting the token_type_ids to the registered buffer in constructor where it is all zeros, which usually occurs
        # when its auto-generated, registered buffer helps users when tracing the model without passing token_type_ids, solves
        # issue #5664
        if token_type_ids is None:
            if hasattr(self, "token_type_ids"):
                # NOTE: We assume either pos ids to have bsz == 1 (broadcastable) or bsz == effective bsz (input_shape[0])
                buffered_token_type_ids = self.token_type_ids.expand(position_ids.shape[0], -1)
                buffered_token_type_ids = torch.gather(buffered_token_type_ids, dim=1, index=position_ids)
                token_type_ids = buffered_token_type_ids.expand(batch_size, seq_length)
            else:
                token_type_ids = torch.zeros(input_shape, dtype=torch.long, device=self.position_ids.device)

        if inputs_embeds is None:
            inputs_embeds = self.word_embeddings(input_ids)
        token_type_embeddings = self.token_type_embeddings(token_type_ids)

        embeddings = inputs_embeds + token_type_embeddings
        if self.position_embedding_type == "absolute":
            position_embeddings = self.position_embeddings(position_ids)
            embeddings += position_embeddings
        embeddings = self.LayerNorm(embeddings)
        embeddings = self.dropout(embeddings)
        return embeddings

    @staticmethod
    def create_position_ids_from_inputs_embeds(inputs_embeds, padding_idx):
        """
        We are provided embeddings directly. We cannot infer which are padded so just generate sequential position ids.

        Args:
            inputs_embeds: torch.Tensor

        Returns: torch.Tensor
        """
        input_shape = inputs_embeds.size()[:-1]
        sequence_length = input_shape[1]

        position_ids = torch.arange(
            padding_idx + 1, sequence_length + padding_idx + 1, dtype=torch.long, device=inputs_embeds.device
        )
        return position_ids.unsqueeze(0).expand(input_shape)

    @staticmethod
    def create_position_ids_from_input_ids(input_ids, padding_idx, past_key_values_length=0):
        """
        Replace non-padding symbols with their position numbers. Position numbers begin at padding_idx+1. Padding symbols
        are ignored. This is modified from fairseq's `utils.make_positions`.

        Args:
            x: torch.Tensor x:

        Returns: torch.Tensor
        """
        # The series of casts and type-conversions here are carefully balanced to both work with ONNX export and XLA.
        mask = input_ids.ne(padding_idx).int()
        incremental_indices = (torch.cumsum(mask, dim=1).type_as(mask) + past_key_values_length) * mask
        return incremental_indices.long() + padding_idx


@auto_docstring
class BridgeTowerPreTrainedModel(PreTrainedModel):
    config: BridgeTowerConfig
    base_model_prefix = "bridgetower"
    supports_gradient_checkpointing = False
    _no_split_modules = ["BridgeTowerSelfAttention", "BridgeTowerResidualAttention"]
    _skip_keys_device_placement = "past_key_values"

    def _init_weights(self, module: nn.Module):
        std = self.config.initializer_factor
        if isinstance(module, BridgeTowerVisionTransformer):
            proj_std = (self.config.hidden_size**-0.5) * ((2 * self.config.num_hidden_layers) ** -0.5)
            attn_std = self.config.hidden_size**-0.5
            fc_std = (2 * self.config.hidden_size) ** -0.5
            for block in module.transformer.resblocks:
                nn.init.normal_(block.attn.in_proj_weight, std=attn_std * std)
                block.attn.in_proj_bias.data.zero_()
                nn.init.normal_(block.attn.out_proj.weight, std=proj_std * std)
                nn.init.normal_(block.mlp.c_fc.weight, std=fc_std * std)
                nn.init.normal_(block.mlp.c_proj.weight, std=proj_std * std)

            nn.init.normal_(module.embeddings.class_embedding, std=attn_std * std)
            nn.init.normal_(module.embeddings.position_embedding.weight, std=attn_std * std)
        elif isinstance(module, (nn.Linear, nn.Conv2d, nn.Embedding)):
            module.weight.data.normal_(mean=0.0, std=0.05 * std)
        elif isinstance(module, nn.LayerNorm):
            module.bias.data.zero_()
            module.weight.data.fill_(1.0)
        elif isinstance(module, BridgeTowerForContrastiveLearning):
            module.logit_scale.data.fill_(self.config.logit_scale_init_value)

        if isinstance(module, (nn.Linear, BridgeTowerMLMHead)) and module.bias is not None:
            module.bias.data.zero_()


class BridgeTowerVisionModel(BridgeTowerPreTrainedModel):
    config: BridgeTowerVisionConfig

    def __init__(self, config):
        super().__init__(config)
        self.visual = BridgeTowerVisionTransformer(config)

    @property
    def dtype(self):
        return self.visual.embeddings.patch_embedding.weight.dtype

    def forward(self, image, image_mask=None, interpolate_pos_encoding=False):
        return self.visual(image.type(self.dtype), image_mask, interpolate_pos_encoding)


@auto_docstring(
    custom_intro="""
    The model can behave as an encoder (with only self-attention) as well as a decoder, in which case a layer of
    cross-attention is added between the self-attention layers, following the architecture described in *Attention is
    all you need*_ by Ashish Vaswani, Noam Shazeer, Niki Parmar, Jakob Uszkoreit, Llion Jones, Aidan N. Gomez, Lukasz
    Kaiser and Illia Polosukhin.

    To behave as an decoder the model needs to be initialized with the `is_decoder` argument of the configuration set
    to `True`. To be used in a Seq2Seq model, the model needs to initialized with both `is_decoder` argument and
    `add_cross_attention` set to `True`; an `encoder_hidden_states` is then expected as an input to the forward pass.

    .. _*Attention is all you need*: https://huggingface.co/papers/1706.03762
    """
)
class BridgeTowerTextModel(BridgeTowerPreTrainedModel):
    config: BridgeTowerTextConfig

    def __init__(self, config, add_pooling_layer=True):
        r"""
        add_pooling_layer (bool, *optional*, defaults to `True`):
            Whether to add a pooling layer
        """
        super().__init__(config)
        self.config = config
        self.gradient_checkpointing = False

        self.embeddings = BridgeTowerTextEmbeddings(config)
        self.encoder = BridgeTowerTextEncoder(config)

        self.pooler = BridgeTowerPooler(config) if add_pooling_layer else None

        # Initialize weights and apply final processing
        self.post_init()

    def get_input_embeddings(self):
        return self.embeddings.word_embeddings

    def set_input_embeddings(self, value):
        self.embeddings.word_embeddings = value

    def _prune_heads(self, heads_to_prune):
        """
        Prunes heads of the model. heads_to_prune: dict of {layer_num: list of heads to prune in this layer} See base
        class PreTrainedModel
        """
        for layer, heads in heads_to_prune.items():
            self.encoder.layer[layer].attention.prune_heads(heads)

    @can_return_tuple
    @auto_docstring
    # NOTE: bridgetower with its multimodality has a more complicated scheme making records harder
    # for now we skip the copies from bert but stay close to the original
    # copied from transformers.models.bert.modeling_bert.BertModel.forward
    def forward(
        self,
        input_ids: Optional[torch.Tensor] = None,
        attention_mask: Optional[torch.Tensor] = None,
        token_type_ids: Optional[torch.Tensor] = None,
        position_ids: Optional[torch.Tensor] = None,
        head_mask: Optional[torch.Tensor] = None,
        inputs_embeds: Optional[torch.Tensor] = None,
        encoder_hidden_states: Optional[torch.Tensor] = None,
        encoder_attention_mask: Optional[torch.Tensor] = None,
        past_key_values: Optional[Union[list[torch.FloatTensor], Cache]] = None,
        use_cache: Optional[bool] = None,
        output_attentions: Optional[bool] = None,
        output_hidden_states: Optional[bool] = None,
        cache_position: Optional[torch.Tensor] = None,
        **kwargs: Unpack[TransformersKwargs],
    ) -> Union[tuple[torch.Tensor], BaseModelOutputWithPoolingAndCrossAttentions]:
        output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
        output_hidden_states = (
            output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
        )

        if self.config.is_decoder:
            use_cache = use_cache if use_cache is not None else self.config.use_cache
        else:
            use_cache = False

        if self.gradient_checkpointing and self.training:
            if use_cache:
                logger.warning_once(
                    "`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`..."
                )
                use_cache = False

        return_legacy_cache = False
        if use_cache and not isinstance(past_key_values, Cache):
            logger.warning_once(
                "Passing a tuple of `past_key_values` is deprecated and will be removed in Transformers v4.58.0. "
                "You should pass an instance of `EncoderDecoderCache` instead, e.g. "
                "`past_key_values=EncoderDecoderCache.from_legacy_cache(past_key_values)`."
            )
            return_legacy_cache = True
            past_key_values = EncoderDecoderCache.from_legacy_cache(past_key_values)

        if (input_ids is None) ^ (inputs_embeds is not None):
            raise ValueError("You must specify exactly one of input_ids or inputs_embeds")

        if input_ids is not None:
            device = input_ids.device
            input_shape = input_ids.shape
        else:
            device = inputs_embeds.device
            input_shape = inputs_embeds.shape[:-1]

        seq_length = input_shape[1]
        past_key_values_length = past_key_values.get_seq_length() if past_key_values is not None else 0
        if cache_position is None:
            cache_position = torch.arange(past_key_values_length, past_key_values_length + seq_length, device=device)

        embedding_output = self.embeddings(
            input_ids=input_ids,
            position_ids=position_ids,
            token_type_ids=token_type_ids,
            inputs_embeds=inputs_embeds,
            past_key_values_length=past_key_values_length,
        )

        attention_mask, encoder_attention_mask = self._create_attention_masks(
            input_shape=input_shape,
            attention_mask=attention_mask,
            encoder_attention_mask=encoder_attention_mask,
            embedding_output=embedding_output,
            encoder_hidden_states=encoder_hidden_states,
            cache_position=cache_position,
            past_key_values=past_key_values,
        )

        # Prepare head mask if needed
        # 1.0 in head_mask indicate we keep the head
        # attention_probs has shape bsz x n_heads x N x N
        # input head_mask has shape [num_heads] or [num_hidden_layers x num_heads]
        # and head_mask is converted to shape [num_hidden_layers x batch x num_heads x seq_length x seq_length]
        head_mask = self.get_head_mask(head_mask, self.config.num_hidden_layers)

        encoder_outputs = self.encoder(
            embedding_output,
            attention_mask=attention_mask,
            head_mask=head_mask,
            encoder_hidden_states=encoder_hidden_states,
            encoder_attention_mask=encoder_attention_mask,
            past_key_values=past_key_values,
            use_cache=use_cache,
            output_attentions=output_attentions,
            output_hidden_states=output_hidden_states,
            cache_position=cache_position,
            position_ids=position_ids,
            **kwargs,
        )
        sequence_output = encoder_outputs[0]
        pooled_output = self.pooler(sequence_output) if self.pooler is not None else None

        if return_legacy_cache:
            encoder_outputs.past_key_values = encoder_outputs.past_key_values.to_legacy_cache()

        return BaseModelOutputWithPoolingAndCrossAttentions(
            last_hidden_state=sequence_output,
            pooler_output=pooled_output,
            past_key_values=encoder_outputs.past_key_values,
            hidden_states=encoder_outputs.hidden_states,
            attentions=encoder_outputs.attentions,
            cross_attentions=encoder_outputs.cross_attentions,
        )

    # Copied from transformers.models.bert.modeling_bert.BertModel._create_attention_masks
    def _create_attention_masks(
        self,
        input_shape,
        attention_mask,
        encoder_attention_mask,
        embedding_output,
        encoder_hidden_states,
        cache_position,
        past_key_values,
    ):
        if attention_mask is not None and attention_mask.dim() == 2:
            if self.config.is_decoder:
                attention_mask = create_causal_mask(
                    config=self.config,
                    input_embeds=embedding_output,
                    attention_mask=attention_mask,
                    cache_position=cache_position,
                    past_key_values=past_key_values,
                )
            else:
                attention_mask = self._update_full_mask(
                    attention_mask,
                    embedding_output,
                )
        elif attention_mask is not None and attention_mask.dim() == 3:
            if "flash" in self.config._attn_implementation or self.config._attn_implementation == "flex_attention":
                raise ValueError(
                    "Passing attention mask with a 3D/4D shape does not work with type "
                    f"{self.config._attn_implementation} - please use either `sdpa` or `eager` instead."
                )
            attention_mask = self.get_extended_attention_mask(attention_mask, input_shape)

        if encoder_attention_mask is not None:
            if encoder_attention_mask.dim() == 2:
                encoder_attention_mask = self._update_cross_attn_mask(
                    encoder_hidden_states,
                    encoder_attention_mask,
                    embedding_output.shape[:2],
                    embedding_output,
                )
            else:
                if "flash" in self.config._attn_implementation or self.config._attn_implementation == "flex_attention":
                    raise ValueError(
                        "Passing attention mask with a 3D/4D shape does not work with type "
                        f"{self.config._attn_implementation} - please use either `sdpa` or `eager` instead."
                    )
                encoder_attention_mask = self.invert_attention_mask(encoder_attention_mask)

        return attention_mask, encoder_attention_mask

    # Copied from transformers.models.bart.modeling_bart.BartPreTrainedModel._update_full_mask
    def _update_full_mask(
        self,
        attention_mask: Union[torch.Tensor, None],
        inputs_embeds: torch.Tensor,
    ):
        if attention_mask is not None:
            if "flash" in self.config._attn_implementation:
                attention_mask = attention_mask if 0 in attention_mask else None
            elif self.config._attn_implementation == "sdpa":
                # output_attentions=True & head_mask can not be supported when using SDPA, fall back to
                # the manual implementation that requires a 4D causal mask in all cases.
                # [bsz, seq_len] -> [bsz, 1, tgt_seq_len, src_seq_len]
                attention_mask = _prepare_4d_attention_mask_for_sdpa(attention_mask, inputs_embeds.dtype)
            elif self.config._attn_implementation == "flex_attention":
                if isinstance(attention_mask, torch.Tensor):
                    attention_mask = make_flex_block_causal_mask(attention_mask, is_causal=False)
            else:
                # [bsz, seq_len] -> [bsz, 1, tgt_seq_len, src_seq_len]
                attention_mask = _prepare_4d_attention_mask(attention_mask, inputs_embeds.dtype)

        return attention_mask

    # Copied from transformers.models.bart.modeling_bart.BartPreTrainedModel._update_cross_attn_mask
    def _update_cross_attn_mask(
        self,
        encoder_hidden_states: Union[torch.Tensor, None],
        encoder_attention_mask: Union[torch.Tensor, None],
        input_shape: torch.Size,
        inputs_embeds: torch.Tensor,
    ):
        # expand encoder attention mask
        if encoder_hidden_states is not None and encoder_attention_mask is not None:
            if "flash" in self.config._attn_implementation:
                encoder_attention_mask = encoder_attention_mask if 0 in encoder_attention_mask else None
            elif self.config._attn_implementation == "sdpa":
                # output_attentions=True & cross_attn_head_mask can not be supported when using SDPA, and we fall back on
                # the manual implementation that requires a 4D causal mask in all cases.
                # [bsz, seq_len] -> [bsz, 1, tgt_seq_len, src_seq_len]
                encoder_attention_mask = _prepare_4d_attention_mask_for_sdpa(
                    encoder_attention_mask,
                    inputs_embeds.dtype,
                    tgt_len=input_shape[-1],
                )
            elif self.config._attn_implementation == "flex_attention":
                if isinstance(encoder_attention_mask, torch.Tensor):
                    encoder_attention_mask = make_flex_block_causal_mask(
                        encoder_attention_mask,
                        query_length=input_shape[-1],
                        is_causal=False,
                    )
            else:
                # [bsz, seq_len] -> [bsz, 1, tgt_seq_len, src_seq_len]
                encoder_attention_mask = _prepare_4d_attention_mask(
                    encoder_attention_mask, inputs_embeds.dtype, tgt_len=input_shape[-1]
                )

        return encoder_attention_mask


@auto_docstring(
    custom_intro="""
    The bare BridgeTower Model transformer outputting BridgeTowerModelOutput object without any specific head on
    """
)
class BridgeTowerModel(BridgeTowerPreTrainedModel):
    def __init__(self, config):
        super().__init__(config)
        self.config = config
        vision_config = config.vision_config
        text_config = config.text_config

        if config.share_cross_modal_transformer_layers:
            self.cross_modal_text_transform = nn.Linear(text_config.hidden_size, config.hidden_size)
            self.cross_modal_image_transform = nn.Linear(vision_config.hidden_size, config.hidden_size)
        else:
            self.cross_modal_text_transform = nn.ModuleList(
                [nn.Linear(text_config.hidden_size, config.hidden_size) for _ in range(config.num_hidden_layers)]
            )
            self.cross_modal_image_transform = nn.ModuleList(
                [nn.Linear(vision_config.hidden_size, config.hidden_size) for _ in range(config.num_hidden_layers)]
            )

        self.token_type_embeddings = nn.Embedding(2, config.hidden_size)

        self.vision_model = BridgeTowerVisionModel(vision_config)

        self.text_model = BridgeTowerTextModel(text_config)

        if not vision_config.share_layernorm and config.init_layernorm_from_vision_encoder:
            for ln in self.vision_model.visual.cross_modal_ln_separate:
                ln.weight.data = self.vision_model.visual.ln_post.weight.data
                ln.bias.data = self.vision_model.visual.ln_post.bias.data

        self.cross_modal_image_layers = nn.ModuleList(
            [BridgeTowerBertCrossLayer(text_config) for _ in range(config.num_hidden_layers)]
        )
        self.cross_modal_text_layers = nn.ModuleList(
            [BridgeTowerBertCrossLayer(text_config) for _ in range(config.num_hidden_layers)]
        )

        # Class token => Linear => Tanh
        self.cross_modal_image_pooler = BridgeTowerPooler(config)
        self.cross_modal_text_pooler = BridgeTowerPooler(config)

        # Initialize BridgeTower Components
        self.cross_modal_text_layernorm = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps)
        self.cross_modal_image_layernorm = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps)

        if config.share_link_tower_layers:
            self.cross_modal_text_link_tower = BridgeTowerLinkTower(config)
            self.cross_modal_image_link_tower = BridgeTowerLinkTower(config)
        else:
            self.cross_modal_text_link_tower = nn.ModuleList(
                [BridgeTowerLinkTower(config) for _ in range(config.num_hidden_layers - 1)]
            )
            self.cross_modal_image_link_tower = nn.ModuleList(
                [BridgeTowerLinkTower(config) for _ in range(config.num_hidden_layers - 1)]
            )

        self.post_init()

    def get_input_embeddings(self):
        return self.text_model.get_input_embeddings()

    def set_input_embeddings(self, value):
        self.text_model.set_input_embeddings(value)

    @auto_docstring
    def forward(
        self,
        input_ids: Optional[torch.LongTensor] = None,
        attention_mask: Optional[torch.FloatTensor] = None,
        token_type_ids: Optional[torch.LongTensor] = None,
        pixel_values: Optional[torch.FloatTensor] = None,
        pixel_mask: Optional[torch.LongTensor] = None,
        head_mask: Optional[torch.FloatTensor] = None,
        inputs_embeds: Optional[torch.FloatTensor] = None,
        image_embeds: Optional[torch.FloatTensor] = None,
        image_token_type_idx: Optional[int] = None,
        output_attentions: Optional[bool] = None,
        output_hidden_states: Optional[bool] = None,
        return_dict: Optional[bool] = None,
        labels: Optional[torch.LongTensor] = None,
        interpolate_pos_encoding: bool = False,
    ) -> Union[tuple[torch.Tensor], BridgeTowerModelOutput]:
        r"""
        image_embeds (`torch.FloatTensor` of shape `(batch_size, num_patches, hidden_size)`, *optional*):
            Optionally, instead of passing `pixel_values`, you can choose to directly pass an embedded representation.
            This is useful if you want more control over how to convert `pixel_values` into patch embeddings.
        image_token_type_idx (`int`, *optional*):
            - The token type ids for images.
        output_hidden_states (`bool`, *optional*):
            If set to `True`, hidden states are returned as a list containing the hidden states of text, image, and
            cross-modal components respectively. i.e. `(hidden_states_text, hidden_states_image,
            hidden_states_cross_modal)` where each element is a list of the hidden states of the corresponding
            modality. `hidden_states_txt/img` are a list of tensors corresponding to unimodal hidden states and
            `hidden_states_cross_modal` is a list of tuples containing `cross_modal_text_hidden_states` and
            `cross_modal_image_hidden_states` of each brdige layer.
        labels (`torch.LongTensor` of shape `(batch_size,)`, *optional*):
            Labels are currently not supported.

        Examples:

        ```python
        >>> from transformers import BridgeTowerProcessor, BridgeTowerModel
        >>> from PIL import Image
        >>> import requests

        >>> # prepare image and text
        >>> url = "http://images.cocodataset.org/val2017/000000039769.jpg"
        >>> image = Image.open(requests.get(url, stream=True).raw)
        >>> text = "hello world"
        >>> processor = BridgeTowerProcessor.from_pretrained("BridgeTower/bridgetower-base")
        >>> model = BridgeTowerModel.from_pretrained("BridgeTower/bridgetower-base")

        >>> inputs = processor(image, text, return_tensors="pt")
        >>> outputs = model(**inputs)
        >>> outputs.keys()
        odict_keys(['text_features', 'image_features', 'pooler_output'])
        ```"""
        output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
        output_hidden_states = (
            output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
        )
        all_hidden_states_text = () if output_hidden_states else None
        all_hidden_states_image = () if output_hidden_states else None
        all_hidden_states_cross = () if output_hidden_states else None
        all_hidden_states = () if output_hidden_states else None
        all_self_attentions = () if output_attentions else None

        if inputs_embeds is not None and input_ids is None:
            raise NotImplementedError(
                "BridgeTowerModel does not use `inputs_embeds`.  Make sure to pass in `input_ids` instead."
            )

        return_dict = return_dict if return_dict is not None else self.config.use_return_dict
        image_token_type_idx = image_token_type_idx if image_token_type_idx else 1
        input_shape = input_ids.size()
        text_embeds = self.text_model.embeddings(input_ids=input_ids)

        if output_hidden_states:
            all_hidden_states_text += (text_embeds,)

        if attention_mask is None:
            attention_mask = torch.ones(input_shape, dtype=torch.long, device=input_ids.device)
        extend_text_masks = self.text_model.get_extended_attention_mask(attention_mask, input_shape).to(
            input_ids.device
        )

        # The split_index determines how many layers of the uni-modal encoder are applied before the cross-modal encoder
        split_index = len(self.text_model.encoder.layer) - self.config.num_hidden_layers + 1

        # Run the first 'split_index' layers of the textual encoder
        for layer in self.text_model.encoder.layer[:split_index]:
            text_embeds = layer(text_embeds, extend_text_masks)[0]

            if output_hidden_states:
                all_hidden_states_text += (text_embeds,)

        if image_embeds is None:
            image_embeds = self.vision_model.visual.forward_pre(
                pixel_values.type(self.vision_model.dtype), interpolate_pos_encoding=interpolate_pos_encoding
            )
        else:
            # Permute as BridgeTowerResidualAttention has batch_first=True
            image_embeds = image_embeds.permute(1, 0, 2)

        if output_hidden_states:
            all_hidden_states_image += (image_embeds,)

        # Run the first 'split_index' layers of the visual encoder
        for block in self.vision_model.visual.transformer.resblocks[:split_index]:
            image_embeds = block(image_embeds)
            if output_hidden_states:
                all_hidden_states_image += (image_embeds,)

        image_embeds_with_ln = self.vision_model.visual.forward_post(image_embeds.type(self.vision_model.dtype))

        # first layer is a special case because we don't have the output from the cross-encoder yet
        cross_modal_text = self.cross_modal_text_transform(text_embeds)

        text_token_type_embeddings = self.token_type_embeddings(
            torch.zeros(1, dtype=torch.long, device=input_ids.device)
        ).expand_as(cross_modal_text)

        cross_modal_text = self.cross_modal_text_layernorm(cross_modal_text + text_token_type_embeddings)

        image_embeds_with_ln = self.cross_modal_image_transform(image_embeds_with_ln)
        image_token_type_embeddings = self.token_type_embeddings(
            torch.full((1,), image_token_type_idx, dtype=torch.long, device=input_ids.device)
        ).expand_as(image_embeds_with_ln)

        image_embeds_with_ln = image_embeds_with_ln + image_token_type_embeddings
        cross_modal_image = self.cross_modal_image_layernorm(image_embeds_with_ln)

        pixel_mask = torch.ones(
            (cross_modal_image.size(0), cross_modal_image.size(1)),
            dtype=torch.long,
            device=input_ids.device,
        )
        extend_image_masks = self.text_model.get_extended_attention_mask(pixel_mask, pixel_mask.size()).to(
            input_ids.device
        )

        layer_outputs_text = self.cross_modal_text_layers[0](
            cross_modal_text,
            cross_modal_image,
            attention_mask=extend_text_masks,
            encoder_attention_mask=extend_image_masks,
            output_attentions=output_attentions,
        )
        cross_text_features = layer_outputs_text[0]

        layer_outputs_image = self.cross_modal_image_layers[0](
            cross_modal_image,
            cross_modal_text,
            attention_mask=extend_image_masks,
            encoder_attention_mask=extend_text_masks,
            output_attentions=output_attentions,
        )
        cross_image_features = layer_outputs_image[0]

        if output_hidden_states:
            all_hidden_states_cross += ((cross_text_features, cross_image_features),)

        if output_attentions:
            all_self_attentions += ((layer_outputs_text[1], layer_outputs_image[1]),)

        link_layer_index = 0

        #  Each of the top 6 layers of the visual and textual encoders ([split_index:]) is connected to each layer of
        #  the cross-modal encoder via bridge layers, which brings bottom-up alignment and fusion to the cross-modal encoder.
        for i in range(split_index, len(self.text_model.encoder.layer)):
            text_embeds = self.text_model.encoder.layer[i](text_embeds, extend_text_masks)[0]
            image_embeds = self.vision_model.visual.transformer.resblocks[i](image_embeds).type(
                self.vision_model.dtype
            )
            image_embeds_with_ln = (
                self.cross_modal_image_transform(self.vision_model.visual.forward_post(image_embeds))
                + image_token_type_embeddings
            )

            text_link_tower = self.cross_modal_text_link_tower[link_layer_index]
            image_link_tower = self.cross_modal_image_link_tower[link_layer_index]

            # Bridge layers for textual and visual encoders
            cross_text_features_ = text_link_tower(
                self.cross_modal_text_transform(text_embeds) + text_token_type_embeddings,
                cross_text_features,
                extend_text_masks,
            )
            cross_image_features_ = image_link_tower(image_embeds_with_ln, cross_image_features, extend_image_masks)

            # Cross-modal encoder via bridge layers of textual and visual encoders
            layer_outputs_text = self.cross_modal_text_layers[link_layer_index + 1](
                cross_text_features_,
                cross_image_features_,
                attention_mask=extend_text_masks,
                encoder_attention_mask=extend_image_masks,
                output_attentions=output_attentions,
            )
            cross_text_features = layer_outputs_text[0]

            layer_outputs_image = self.cross_modal_image_layers[link_layer_index + 1](
                cross_image_features_,
                cross_text_features_,
                attention_mask=extend_image_masks,
                encoder_attention_mask=extend_text_masks,
                output_attentions=output_attentions,
            )
            cross_image_features = layer_outputs_image[0]

            link_layer_index += 1

            if output_hidden_states:
                all_hidden_states_text += (text_embeds,)
                all_hidden_states_image += (image_embeds,)
                all_hidden_states_cross += ((cross_text_features, cross_image_features),)

            if output_attentions:
                all_self_attentions += ((layer_outputs_text[1], layer_outputs_image[1]),)

        #  Concatenate the cls token of the text and image features to get the final represtation
        text_features, image_features = cross_text_features, cross_image_features
        cls_features = self.get_cls_features(text_features, image_features)

        if output_hidden_states:
            all_hidden_states = (all_hidden_states_text, all_hidden_states_image, all_hidden_states_cross)

        if not return_dict:
            return tuple(
                v
                for v in [text_features, image_features, cls_features, all_hidden_states, all_self_attentions]
                if v is not None
            )

        return BridgeTowerModelOutput(
            text_features=text_features,
            image_features=image_features,
            pooler_output=cls_features,
            hidden_states=all_hidden_states,
            attentions=all_self_attentions,
        )

    def get_cls_features(self, text_features, image_features):
        cls_features_text = self.cross_modal_text_pooler(text_features)
        cls_features_image = self.cross_modal_image_pooler(image_features)
        return torch.cat([cls_features_text, cls_features_image], dim=-1)


# Copied from transformers.models.vilt.modeling_vilt.ViltPredictionHeadTransform with Vilt->BridgeTower
class BridgeTowerPredictionHeadTransform(nn.Module):
    def __init__(self, config):
        super().__init__()
        self.dense = nn.Linear(config.hidden_size, config.hidden_size)
        if isinstance(config.hidden_act, str):
            self.transform_act_fn = ACT2FN[config.hidden_act]
        else:
            self.transform_act_fn = config.hidden_act
        self.LayerNorm = nn.LayerNorm(config.hidden_size, eps=config.layer_norm_eps)

    def forward(self, hidden_states):
        hidden_states = self.dense(hidden_states)
        hidden_states = self.transform_act_fn(hidden_states)
        hidden_states = self.LayerNorm(hidden_states)
        return hidden_states


class BridgeTowerMLMHead(nn.Module):
    def __init__(self, config, weight=None):
        super().__init__()
        self.config = config
        self.transform = BridgeTowerPredictionHeadTransform(config)
        self.decoder = nn.Linear(config.hidden_size, config.text_config.vocab_size, bias=False)
        self.bias = nn.Parameter(torch.zeros(config.text_config.vocab_size))
        if weight is not None:
            self.decoder.weight = weight

    def forward(self, x):
        mlm_score = self.transform(x)
        mlm_score = self.decoder(mlm_score) + self.bias
        return mlm_score


class BridgeTowerITMHead(nn.Module):
    def __init__(self, hidden_size):
        super().__init__()
        self.fc = nn.Linear(hidden_size, 2)

    def forward(self, x):
        itm_score = self.fc(x)
        return itm_score


@auto_docstring(
    custom_intro="""
    BridgeTower Model with a language modeling head on top as done during pretraining.
    """
)
class BridgeTowerForMaskedLM(BridgeTowerPreTrainedModel):
    _tied_weights_keys = ["mlm_score.decoder.weight"]

    def __init__(self, config):
        super().__init__(config)

        self.bridgetower = BridgeTowerModel(config)
        self.mlm_score = BridgeTowerMLMHead(config)

        # Initialize weights and apply final processing
        self.post_init()

    def get_output_embeddings(self):
        return self.mlm_score.decoder

    def set_output_embeddings(self, new_embeddings):
        self.mlm_score.decoder = new_embeddings

    @auto_docstring
    def forward(
        self,
        input_ids: Optional[torch.LongTensor] = None,
        attention_mask: Optional[torch.FloatTensor] = None,
        token_type_ids: Optional[torch.LongTensor] = None,
        pixel_values: Optional[torch.FloatTensor] = None,
        pixel_mask: Optional[torch.LongTensor] = None,
        head_mask: Optional[torch.FloatTensor] = None,
        inputs_embeds: Optional[torch.FloatTensor] = None,
        image_embeds: Optional[torch.FloatTensor] = None,
        output_attentions: Optional[bool] = None,
        output_hidden_states: Optional[bool] = None,
        return_dict: Optional[bool] = None,
        labels: Optional[torch.LongTensor] = None,
    ) -> Union[MaskedLMOutput, tuple[torch.FloatTensor]]:
        r"""
        image_embeds (`torch.FloatTensor` of shape `(batch_size, num_patches, hidden_size)`, *optional*):
            Optionally, instead of passing `pixel_values`, you can choose to directly pass an embedded representation.
            This is useful if you want more control over how to convert `pixel_values` into patch embeddings.
        labels (`torch.LongTensor` of shape `(batch_size, sequence_length)`, *optional*):
            Labels for computing the masked language modeling loss. Indices should be in `[-100, 0, ...,
            config.vocab_size]` (see `input_ids` docstring) Tokens with indices set to `-100` are ignored (masked), the
            loss is only computed for the tokens with labels in `[0, ..., config.vocab_size]`

        Examples:

        ```python
        >>> from transformers import BridgeTowerProcessor, BridgeTowerForMaskedLM
        >>> from PIL import Image
        >>> import requests

        >>> url = "http://images.cocodataset.org/val2017/000000360943.jpg"
        >>> image = Image.open(requests.get(url, stream=True).raw).convert("RGB")
        >>> text = "a <mask> looking out of the window"

        >>> processor = BridgeTowerProcessor.from_pretrained("BridgeTower/bridgetower-base-itm-mlm")
        >>> model = BridgeTowerForMaskedLM.from_pretrained("BridgeTower/bridgetower-base-itm-mlm")

        >>> # prepare inputs
        >>> encoding = processor(image, text, return_tensors="pt")

        >>> # forward pass
        >>> outputs = model(**encoding)

        >>> results = processor.decode(outputs.logits.argmax(dim=-1).squeeze(0).tolist())

        >>> print(results)
        .a cat looking out of the window.
        ```"""
        return_dict = return_dict if return_dict is not None else self.config.use_return_dict
        outputs = self.bridgetower(
            input_ids,
            attention_mask=attention_mask,
            token_type_ids=token_type_ids,
            pixel_values=pixel_values,
            pixel_mask=pixel_mask,
            head_mask=head_mask,
            inputs_embeds=inputs_embeds,
            image_embeds=image_embeds,
            output_attentions=output_attentions,
            output_hidden_states=output_hidden_states,
            return_dict=return_dict,
        )

        mlm_logits = self.mlm_score(outputs.text_features if return_dict else outputs[0])
        masked_lm_loss = None
        if labels is not None:
            loss_fct = CrossEntropyLoss()  # -100 index = padding token

            labels = labels.to(mlm_logits.device)
            masked_lm_loss = loss_fct(mlm_logits.view(-1, self.config.text_config.vocab_size), labels.view(-1))

        if not return_dict:
            output = tuple(mlm_logits)
            return ((masked_lm_loss,) + output) if masked_lm_loss is not None else output

        return MaskedLMOutput(
            loss=masked_lm_loss,
            logits=mlm_logits,
            hidden_states=outputs.hidden_states,
            attentions=outputs.attentions,
        )


@auto_docstring(
    custom_intro="""
    BridgeTower Model transformer with a classifier head on top (a linear layer on top of the final hidden state of the
    [CLS] token) for image-to-text matching.
    """
)
class BridgeTowerForImageAndTextRetrieval(BridgeTowerPreTrainedModel):
    def __init__(self, config):
        super().__init__(config)

        self.bridgetower = BridgeTowerModel(config)

        self.itm_score = BridgeTowerITMHead(config.hidden_size * 2)

        # Initialize weights and apply final processing
        self.post_init()

    @auto_docstring
    def forward(
        self,
        input_ids: Optional[torch.LongTensor] = None,
        attention_mask: Optional[torch.FloatTensor] = None,
        token_type_ids: Optional[torch.LongTensor] = None,
        pixel_values: Optional[torch.FloatTensor] = None,
        pixel_mask: Optional[torch.LongTensor] = None,
        head_mask: Optional[torch.FloatTensor] = None,
        inputs_embeds: Optional[torch.FloatTensor] = None,
        image_embeds: Optional[torch.FloatTensor] = None,
        output_attentions: Optional[bool] = None,
        output_hidden_states: Optional[bool] = None,
        return_dict: Optional[bool] = None,
        labels: Optional[torch.LongTensor] = None,
    ) -> Union[SequenceClassifierOutput, tuple[torch.FloatTensor]]:
        r"""
        image_embeds (`torch.FloatTensor` of shape `(batch_size, num_patches, hidden_size)`, *optional*):
            Optionally, instead of passing `pixel_values`, you can choose to directly pass an embedded representation.
            This is useful if you want more control over how to convert `pixel_values` into patch embeddings.
        labels (`torch.LongTensor` of shape `(batch_size, 1)`, *optional*):
            Labels for computing the image-text matching loss. 0 means the pairs don't match and 1 means they match.
            The pairs with 0 will be skipped for calculation.

        Examples:

        ```python
        >>> from transformers import BridgeTowerProcessor, BridgeTowerForImageAndTextRetrieval
        >>> import requests
        >>> from PIL import Image

        >>> url = "http://images.cocodataset.org/val2017/000000039769.jpg"
        >>> image = Image.open(requests.get(url, stream=True).raw)
        >>> texts = ["An image of two cats chilling on a couch", "A football player scoring a goal"]

        >>> processor = BridgeTowerProcessor.from_pretrained("BridgeTower/bridgetower-base-itm-mlm")
        >>> model = BridgeTowerForImageAndTextRetrieval.from_pretrained("BridgeTower/bridgetower-base-itm-mlm")

        >>> # forward pass
        >>> scores = dict()
        >>> for text in texts:
        ...     # prepare inputs
        ...     encoding = processor(image, text, return_tensors="pt")
        ...     outputs = model(**encoding)
        ...     scores[text] = outputs.logits[0, 1].item()
        ```"""
        return_dict = return_dict if return_dict is not None else self.config.use_return_dict

        outputs = self.bridgetower(
            input_ids,
            attention_mask=attention_mask,
            token_type_ids=token_type_ids,
            pixel_values=pixel_values,
            pixel_mask=pixel_mask,
            head_mask=head_mask,
            inputs_embeds=inputs_embeds,
            image_embeds=image_embeds,
            output_attentions=output_attentions,
            output_hidden_states=output_hidden_states,
            return_dict=return_dict,
        )

        pooler_output = outputs.pooler_output if return_dict else outputs[2]

        logits = self.itm_score(pooler_output)

        itm_loss = None
        if labels is not None:
            loss_fct = CrossEntropyLoss()

            labels = labels.to(logits.device)
            itm_loss = loss_fct(logits, labels)

        if not return_dict:
            output = tuple(logits)
            return ((itm_loss,) + output) if itm_loss is not None else output

        return SequenceClassifierOutput(
            loss=itm_loss,
            logits=logits,
            hidden_states=outputs.hidden_states,
            attentions=outputs.attentions,
        )


class BridgeTowerContrastiveHead(nn.Module):
    def __init__(self, hidden_size, embed_size):
        super().__init__()
        self.fc = nn.Linear(hidden_size, embed_size)

    def forward(self, x):
        x = self.fc(x)
        return x


@auto_docstring(
    custom_intro="""
    BridgeTower Model with a image-text contrastive head on top computing image-text contrastive loss.
    """
)
class BridgeTowerForContrastiveLearning(BridgeTowerPreTrainedModel):
    def __init__(self, config):
        super().__init__(config)

        self.bridgetower = BridgeTowerModel(config)

        self.itc_text_head = BridgeTowerContrastiveHead(config.hidden_size, config.contrastive_hidden_size)
        self.itc_image_head = BridgeTowerContrastiveHead(config.hidden_size, config.contrastive_hidden_size)
        self.itc_cross_modal_head = BridgeTowerContrastiveHead(config.hidden_size * 2, config.contrastive_hidden_size)

        self.logit_scale = nn.Parameter(torch.tensor(self.config.logit_scale_init_value))
        # Initialize weights and apply final processing
        self.post_init()

    @auto_docstring
    def forward(
        self,
        input_ids: Optional[torch.LongTensor] = None,
        attention_mask: Optional[torch.FloatTensor] = None,
        token_type_ids: Optional[torch.LongTensor] = None,
        pixel_values: Optional[torch.FloatTensor] = None,
        pixel_mask: Optional[torch.LongTensor] = None,
        head_mask: Optional[torch.FloatTensor] = None,
        inputs_embeds: Optional[torch.FloatTensor] = None,
        image_embeds: Optional[torch.FloatTensor] = None,
        output_attentions: Optional[bool] = None,
        output_hidden_states: Optional[bool] = True,
        return_dict: Optional[bool] = None,
        return_loss: Optional[bool] = None,
    ) -> Union[BridgeTowerContrastiveOutput, tuple[torch.FloatTensor]]:
        r"""
        image_embeds (`torch.FloatTensor` of shape `(batch_size, num_patches, hidden_size)`, *optional*):
            Optionally, instead of passing `pixel_values`, you can choose to directly pass an embedded representation.
            This is useful if you want more control over how to convert `pixel_values` into patch embeddings.
        return_loss (`bool`, *optional*):
            Whether or not to return the contrastive loss.

        Examples:

        ```python
        >>> from transformers import BridgeTowerProcessor, BridgeTowerForContrastiveLearning
        >>> import requests
        >>> from PIL import Image
        >>> import torch

        >>> image_urls = [
        ...     "https://farm4.staticflickr.com/3395/3428278415_81c3e27f15_z.jpg",
        ...     "http://images.cocodataset.org/val2017/000000039769.jpg",
        ... ]
        >>> texts = ["two dogs in a car", "two cats sleeping on a couch"]
        >>> images = [Image.open(requests.get(url, stream=True).raw) for url in image_urls]

        >>> processor = BridgeTowerProcessor.from_pretrained("BridgeTower/bridgetower-large-itm-mlm-itc")
        >>> model = BridgeTowerForContrastiveLearning.from_pretrained("BridgeTower/bridgetower-large-itm-mlm-itc")

        >>> inputs = processor(images, texts, padding=True, return_tensors="pt")
        >>> loss = model(**inputs, return_loss=True).loss

        >>> inputs = processor(images, texts[::-1], padding=True, return_tensors="pt")
        >>> loss_swapped = model(**inputs, return_loss=True).loss

        >>> print("Loss", round(loss.item(), 4))
        Loss 0.0019

        >>> print("Loss with swapped images", round(loss_swapped.item(), 4))
        Loss with swapped images 2.126
        ```"""
        return_dict = return_dict if return_dict is not None else self.config.use_return_dict

        outputs = self.bridgetower(
            input_ids,
            attention_mask=attention_mask,
            token_type_ids=token_type_ids,
            pixel_values=pixel_values,
            pixel_mask=pixel_mask,
            head_mask=head_mask,
            inputs_embeds=inputs_embeds,
            image_embeds=image_embeds,
            output_attentions=output_attentions,
            output_hidden_states=True,
            return_dict=return_dict,
        )

        pooler_output = outputs.pooler_output if return_dict else outputs[2]
        hidden_states_txt, hidden_states_img, hidden_states_cross_modal = (
            outputs.hidden_states if return_dict else outputs[3]
        )

        text_embeds = hidden_states_txt[-1]
        image_embeds = hidden_states_img[-1]

        image_embeds_with_ln = self.bridgetower.vision_model.visual.forward_post(image_embeds)
        image_token_type_embeddings = self.bridgetower.token_type_embeddings(
            torch.full((1,), 1, dtype=torch.long, device=self.bridgetower.token_type_embeddings.weight.device)
        ).expand_as(image_embeds_with_ln)

        image_embeds = self.bridgetower.cross_modal_image_transform(image_embeds_with_ln) + image_token_type_embeddings

        # normalized features
        text_embeds = nn.functional.normalize(self.itc_text_head(text_embeds[:, 0, :]), dim=-1, p=2)
        image_embeds = nn.functional.normalize(self.itc_image_head(image_embeds[:, 0, :]), dim=-1, p=2).to(
            device=text_embeds.device
        )
        cross_embeds = nn.functional.normalize(self.itc_cross_modal_head(pooler_output), dim=-1, p=2).to(
            device=text_embeds.device
        )

        logits = torch.stack([text_embeds, image_embeds, cross_embeds], dim=-2)

        logit_scale = self.logit_scale.exp().to(device=text_embeds.device)
        logits_text_to_image = torch.matmul(text_embeds, image_embeds.t()) * logit_scale
        logits_text_to_cross = torch.matmul(text_embeds, cross_embeds.t()) * logit_scale
        logits_image_to_cross = torch.matmul(image_embeds, cross_embeds.t()) * logit_scale

        itc_loss = None

        if return_loss:
            labels = torch.arange(len(logits), device=logits.device)
            text_to_image_loss = nn.functional.cross_entropy(logits_text_to_image, labels)
            text_to_cross_loss = nn.functional.cross_entropy(logits_text_to_cross, labels)
            image_to_cross_loss = nn.functional.cross_entropy(logits_image_to_cross, labels)
            itc_loss = (text_to_image_loss + text_to_cross_loss + image_to_cross_loss) / 3.0

        if not return_dict:
            output = (logits, text_embeds, image_embeds, cross_embeds) + outputs[3:]
            return ((itc_loss,) + output) if itc_loss is not None else output

        return BridgeTowerContrastiveOutput(
            loss=itc_loss,
            logits=logits,
            text_embeds=text_embeds,
            image_embeds=image_embeds,
            cross_embeds=cross_embeds,
            hidden_states=outputs.hidden_states,
            attentions=outputs.attentions,
        )


__all__ = [
    "BridgeTowerForContrastiveLearning",
    "BridgeTowerForImageAndTextRetrieval",
    "BridgeTowerForMaskedLM",
    "BridgeTowerModel",
    "BridgeTowerPreTrainedModel",
]
